#include <bits/stdc++.h>
 
using namespace std;
 
#define DEBUG(x) cerr<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cerr<<#v<<":";for(int i=0;i<v.size();i++) cerr<<" "<<v[i]; cerr<<endl;
#define DEBUG_MAT(v) cerr<<#v<<endl;for(int i=0;i<v.size();i++){for(int j=0;j<v[i].size();j++) {cerr<<v[i][j]<<" ";}cerr<<endl;}
typedef long long ll;
#define int ll
 
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
#define pll pair<ll,ll>
template<class S, class T> pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first + t.first, s.second + t.second); }
template<class S, class T> pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first - t.first, s.second - t.second); }
template<class S, class T> ostream& operator<<(ostream& os, pair<S, T> p) { os << "(" << p.first << ", " << p.second << ")"; return os; }
#define X first
#define Y second
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define rep1(i,n) for(int i=1;i<=(int)(n);i++)
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;i--)
#define rrep1(i,n) for(int i=(int)(n);i>0;i--)
#define REP(i,a,b) for(int i=a;i<b;i++)
#define in(x, a, b) (a <= x && x < b)
#define all(c) c.begin(),c.end()
template<class T> bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a = b; return 1; } return 0; }
#define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end());
const ll inf = 1000000001;
const ll INF = (ll)1e18 + 1;
const long double pi = 3.1415926535897932384626433832795028841971L;
#define Sp(p) cout<<setprecision(25)<< fixed<<p<<endl;
//int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
//int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };
vi dx = {1, 0, -1, 0}, dy = {0, 1, 0, -1};
vi dx2 = { 1,1,0,-1,-1,-1,0,1 }, dy2 = { 0,1,1,1,0,-1,-1,-1 };
#define fio() cin.tie(0); ios::sync_with_stdio(false);
const ll MOD = 1000000007;
//const ll MOD = 998244353;
// #define mp make_pair
//#define endl '\n'



class UnionFind {
public:
  int n;
  vi par; //�e
  vi ran; //�؂̐[��
  vi num; //�v�f��
  int g; // group��
 
  UnionFind(int _n) {
    n = _n;
    g = n;
    par.resize(n); ran.resize(n); num.resize(n);
    for (int i = 0; i < n; i++) {
      par[i] = i; ran[i] = 0; num[i] = 1;
    }
  }
 
  //�؂̍������߂�
  int find(int x) {
    if (par[x] == x) {
      return x;
    }
    else {
      return par[x] = find(par[x]);
    }
  }
 
  //x��y�̑�����W���𕹍�
  void unite(int x, int y) {
    x = find(x); y = find(y);
    int numsum = num[x] + num[y];
    if (x == y) {
      return;
    }
    if (ran[x]<ran[y]) {
      par[x] = y;
    }
    else {
      par[y] = x;
      if (ran[x] == ran[y]) {
        ran[x]++;
      }
    }
    num[x] = num[y] = numsum;
    g--;
  }
 
  //x��y�������W���ɑ����邩�ۂ�
  bool same(int x, int y) {
    return find(x) == find(y);
  }
 
};


// https://satanic0258.github.io/snippets/data-structure/SegmentMap.html
// #### attention! : [l, r] ( include r, not [l, r) )
// if merge [l, m] and [m + 1, r], flagToMergeAdjacentSegment = true;
class RangeSet: public set<pair<long long, long long>> {
private:
  bool flagToMergeAdjacentSegment;
public:
  RangeSet() {}
  RangeSet(bool flagToMergeAdjacentSegment) : flagToMergeAdjacentSegment(flagToMergeAdjacentSegment) {}

  // get the iterator that x is in
  // noexist -> map.end()
  auto get(ll x) const {
    auto itr = upper_bound(pll(x, 1e18));
    if (itr == begin() or (--itr)->second < x) return end();
    return itr;
  }

  // insert segment [l, r]
  // return merged range
  auto add(pll lr) {
    while (true) {
      auto itr = lower_bound(pll(lr.first, -INF));
      if (itr == end()) break;
      ll r = -INF;
      if (itr->first <= lr.second + (int)flagToMergeAdjacentSegment) r = max(lr.second, itr->second);
      if (r == -INF) break;
      lr.second = r;
      erase(itr);
    }

    while (true) {
      auto itr = lower_bound(pll(lr.first, -INF));
      if (itr == begin()) break;
      itr--;
      ll l = INF;
      ll r = -INF;
      if (itr->second + (int)flagToMergeAdjacentSegment >= lr.first) {
        l = min(lr.first, itr->first);
        r = max(lr.second, itr->second);
      }
      if (l == INF) break;
      lr.first = l;
      lr.second = r;
      erase(itr);
    }
    insert(lr);
    return lower_bound(lr);
  }

  // Are x1 and x2 in the same range?
  bool same(ll x1, ll x2) {
    auto itr = get(x1);
    return itr != end() and (itr->first <= x2 and x2 <= itr->second);
  }
};


signed main() {
  int d, q;
  cin >> d >> q;
  ll ans = 0;
  RangeSet st(true);
  while (q--) {
    int a, b;
    cin >> a >> b;
    auto itr = st.add(pll(a, b));
    chmax(ans, itr->second - itr->first + 1);
    cout << ans << endl;
    // // for (auto itr = st.begin(); itr != st.end(); itr++) {
    // //   cout << *itr << " ";
    // // }
    // cout << endl;
  }
}